In some of the conventionally available methods for measuring a blood glucose level, an analytical instrument is used. In an example of the method, a user inserts the analytical instrument into a portable blood glucose level measuring device, and drips blood on the analytical instrument so that a glucose level of the blood can be automatically measured in the blood glucose level measuring device.
Some of the methods for measuring the blood glucose level employ an electrochemical process. In a case where the electrochemical process is employed in the measurement of the blood glucose level, the analytical instrument is provided with electrodes used for voltage application, while the blood glucose level measuring device is adapted to apply a voltage to the electrodes of the analytical instrument and measure a response current generated then.
In an example of the blood glucose level measuring devices which were proposed so far, a mechanism for disposing of the analytical instrument is provided as illustrated in FIG. 13 so that the user can remove the analytical instrument from the blood glucose level measuring device without any contact with the analytical instrument (for example, see the Patent Documents 1 and 2)
A blood glucose level measuring device 9 illustrated in the drawing is adapted to analyze a specimen using an analytical instrument 90 according to the electrochemical process, and includes a connector portion 91 and an operation knob 92.
As illustrated in FIGS. 13 and 14, the connector portion 91 serves to retain the analytical instrument 90 and includes a plurality of terminals 94 to be in contact with electrodes 93 of the analytical instrument 90. The plurality of terminals 94 apply a voltage to the electrodes 93 of the analytical instrument 90 and measures a response current generated then. In each of the plurality of terminals 94, an edge portion 95 is formed in a shape of a flat spring and contacts the electrode 93 of the analytical instrument 90 at a contact point 96. These terminals 94 are placed so that the edge portions 95 (contact points 96) are linearly aligned in a direction orthogonal to a disposal direction D1.
The operation knob 92 is used to disposing of the analytical instrument 90 mounted in the connector portion 91 and adapted to be slidable in the D1 and D2 directions. The operation knob 92 includes an acting portion 98 for pushing and thereby transferring the analytical instrument 90.
In the blood glucose level measuring device 9, when the analytical instrument 90 is inserted thereinto through an insertion port 97, the terminals 94 of the connector portion 91 contact the electrodes 93 of the analytical instrument 90. When the contact is made, in the edge portions 95 of the plurality of terminals 94, which are provided in the form of the flat spring, the contact positions 96 thereof to contact the analytical instrument 90 are displaced upward as illustrated in FIGS. 15A and 15B. Accordingly, the electrodes 93 of the analytical instrument 90 are pressed by the edge portions 95 of the terminals 94. Thus, the edge portions 95 (contact points 96) of the terminals 94 and the electrodes 93 of the analytical instrument 90 thereby unfailingly contact with each other. In this state, the voltage can be applied to the electrodes 93 of the analytical instrument 90 retained by the connector portion 91, and the response current can be measured. Then, the blood glucose level measuring device 9 can measure a glucose concentration of the blood (blood glucose level) supplied to the analytical instrument 90 based on the response current.
When the measurement of the blood glucose level is completed, the operation knob 92 is transferred in the D1 direction as illustrated in FIG. 13 so that the analytical instrument 90 can be disposed of from the blood glucose level measuring device 9. More specifically, when the operation knob 92 is transferred in the D1 direction, the acting portion 98 of the operation knob 92 pushes an end surface 99 of the analytical instrument 90, and the operation knob 92 is thereby transferred in the D1 direction. As a result, the analytical instrument 90 is finally pushed out of the device in the D1 direction.
When the analytical instrument 90 is fitted in the device, however, the edge portion 95 (contact point 96) in the plurality of terminals 94 is displaced more upward than in a natural state and energized downward as illustrated in FIG. 15B. Therefore, the edge portion 95 (contact point 96) in the plurality of terminals 94 moves downward as it moves away from the analytical instrument 90 and finally returns to the natural state as illustrated in FIG. 15C during the transportation of the analytical instrument 90 in the D1 direction. As a result, an elastic restoring force of the edge portion 95 of the terminal 94 is exerted to the analytical instrument 90 as a force which pushes the analytical instrument 90 in the D1 direction as the edge portion 95 (contact point 96) in the plurality of terminals 94 moves away from the analytical instrument 90. The contact points 96 of the plurality of terminals 94 are aligned in the direction orthogonal to the disposal direction D1 as described referring to FIG. 14. Therefore, the analytical instrument 90 is subject to a load from each of the plurality of terminals 94 almost at the same time. As an unfavorable outcome thereby caused, the analytical instrument 90 may jump out of the device through the insertion port 97 (see FIG. 13) due to such a large load from the plurality of terminals 94 acting on the analytical instrument 90 in the disposal direction D1.
Further, it is necessary to increase the energizing force of the edge portions 95 of the plurality of terminals 94 to be applied to the analytical instrument 90 in order to suitably retain the analytical instrument 90 in the connector portion 91. As a result, it is necessary for a relatively large load from the acting portion 98 of the operation knob 92 to be applied to the analytical instrument 90 in the D1 direction when the analytical instrument 90 is disposed of. Thus, the analytical instrument 90 is inevitably subject to such a relatively large load from the operation knob 92 in addition to the elastic restoring force from the edge portions 95 when the edge portions 95 (contact points 96) of the plurality of terminals 94 move away. These load and force applied to the analytical instrument 90 consequently push the analytical instrument 90 out of the device through the insertion port 97 more often and farther than expected.
When the analytical instrument 90 thus pops out, it may not be possible to dispose of the analytical instrument 90 as originally planned. The blood contained in the analytical instrument 90 is likely to spatter in a location where it is dropped, which possibly causes infections in people nearby, or one who may pickup and dispose of the analytical instrument 90 possibly touches the blood in the analytical instrument 90 by mistake and suffers from infections.
Patent Literature 1: Japanese Unexamined Patent KOKAI Publication No. 2003-114213
Patent Literature 2: Japanese Unexamined Patent KOKAI Publication No. 2001-33418